Troubleshooting Solid 88 Error Code on MRCOOL Mini Split Air Handlers

A solid 88 error code on your MRCOOL mini-split air handler typically signals a power supply issue or control board malfunction. This guide provides step-by-step instructions to identify and resolve the problem.

• Power Reset:

  • Turn off the breaker supplying power to the unit.
  • Wait 15 minutes, then restore power and check if the error clears.

• Inspect Display and Control Board Connections:

  • Turn off power at the breaker for safety.
  • Remove the panel to access the internal wiring.
  • Verify all connections between the display panel and the control board are secure.

• Blower Wheel Check:

  • Lower the louver (front grille) to access the blower wheel.
  • Spin the blower wheel gently using a tool. It should move freely. A stuck or frozen wheel may cause the error.

• Voltage Check (Similar to EL01/E1 Error):

  • If connections and the blower wheel are fine, test the system’s voltage following EL01/E1 error procedures.